Triptorelin C64H82N18O13, Pyr-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2 is a synthetic analogue of gonadorelin (GnRH). As a result of the substitution of the 6th amino acid residue in the native molecule, the agonistic effect is more pronounced and the plasma half-life prolonged.